1H nuclear magnetic resonance investigation of synovial fluid components in osteoarthritis, rheumatoid arthritis and traumatic effusions.

The levels of a range of components were measured by 1H nuclear magnetic resonance (1H NMR) in samples of synovial fluid taken from three groups of patients: 10 with osteoarthritis (OA), 18 with rheumatoid arthritis (RA), and 11 with traumatic effusions. A large number of low molecular weight species were measured simultaneously in addition to triglycerides and glycoproteins. Large variations were found between individuals in any one disease group, and there was no measurable correlation between disease state and levels of any low molecular weight component. However, patients with traumatic effusions had high levels of saturated triglycerides, while those with OA had low levels. The chain length of the triglycerides found in OA synovial fluid appears to be shorter than that for the other groups. In RA the composition of triglycerides appears normal, while the overall level is slightly above normal. In a separate study, serial samples of synovial fluid drawn from the knees of two arthritic patients were examined, and the concentrations of glycoprotein, triglycerides and creatinine were found to show a reasonable correlation with each other and with systemic measures of disease activity. These data suggest the potential of synovial fluid triglycerides and creatinine as inflammatory markers.